I am using it in Castelia City, to find Eevee lvl 19, but nothing is coming?
The 19 level eevee is the highest level Pokemon in the dark grass. So you have to try it in the dark grass not in normal. But if your having the same problem in the DG then its because of the low encounter rate keep trying and you will get it. By the way your leading Pokemon have to be level 19.